Color images are formed by subjecting an exposed silver halide photographic light-sensitive material to color development, in which an oxidized aromatic primary amine color developing agent is reacted with a dye-forming coupler to form a dye in the exposed area.
In general, color reproduction by the subtractive process is used in this photographic process and thereby yellow, magenta and cyan images are formed.
As a photographic coupler for yellow image formation, acylacetanilide type couplers, for example, are used. Couplers for magenta image formation include pyrazolone, pyrazolobenzimidazole, pyrazolotriazole and indazolone type couplers. And couplers for cyan image formation include phenol and naphthol type couplers.
Dye images so-obtained are required to have excellent spectral absorption characteristics and not to discolor even when exposed to light or stored under high temperature and high humidity conditions for a long time.
However, phenol type and naphthol type couplers which have been used and studied as a cyan dye image forming coupler are not necessarily satisfactory in spectral absorption characteristics, heat stability, moisture stability and light fastness of cyan images formed therefrom. Although various proposes including contrivances on the substituent have been made to develop a compound improved in these points, no compound has so far succeeded in satisfying all of them.